The present invention relates to using a signaling control point to act as a home location register for a wireless or wireline telephone switch that supports internet protocol (IP) telephony.
Currently, wireless subscriber profile data is configured in a home location register (HLR). The HLR resides either on a computing module (CM) which is an end office telephony switch or in an off-board node that supports IS-41 protocol signaling. The subscriber data profile is retrieved from the HLR upon registration and stored in a visitor location register (VLR) while the subscriber is actively roaming. By contrast, wireline subscriber profile data, which includes internet (IP) telephones, is stored within the computing module in the form of table data. Wireline subscribers currently do not have public switching telephone network (PSTN) roaming capability.
The present invention addresses several shortcomings of the current configuration. First, the current subscriber profile data in the computing module does not provide the ability to map E.164 telephone directory numbers into internet addresses, e-mail addresses or universal resource locators (URLs) as may be used by IP telephones. Second, current systems have no provision for wireline mobility because an assumption is made that the address of a wireline is fixed, tied to a physical interface, and only moved by changes to the provisioned tables.
As with standard wireline telephony subscribers, IP telephony subscribers are assigned a standard ten (10) digit E.164 directory number (hereinafter xe2x80x9cdirectory numberxe2x80x9d) comprised of a three (3) digit area code, a three (3) digit exchange within the area code, and a four (4) digit unique extension within the exchange. When a call is incoming to the central office of a subscriber""s home service area which supports computer network telephony, such as for instance IP telephony, a signaling control point translates the directory number into an IP address, URL address, or electronic mail address much the same that a local number portability node re-routes calls for non-IP telephony systems. The signaling control point is signaled from an advanced intelligent network (AIN) termination attempt trigger point and provides the directory number of an H.323 gateway and the IP address of the subscriber""s H.323 IP telephony end point. If the subscriber has de-registered from the signaling control point, an overflow route to a land line or voice mail is provided.
Local number routing (LNR) fields are re-used with the local number becoming the ten (10) digit directory number of the gateway, and the called directory number (CDN) becoming the IP address, or a new transmission control application protocol (TCAP) field could be introduced specifically for the IP address.
When a subscriber is roaming in another network, the roamed into (visited) gateway signals back to the home location register/signaling control point of the subscriber""s network and registers its (i.e., the visited gateway""s) public switching telephone network telephone directory number and the IP address assigned to the subscriber while connected to the visited network. When subsequent calls are incoming to the subscriber""s home network switch, the home location register/signaling control point provides the ten (10) digit directory number of the visited gateway and the new IP address rather than the home gateway telephone number and IP address of the subscriber.
This provides the subscriber with a virtual private network for placing telephone calls over IP terminals. Thus, subscribers have the ability to roam among networks and continue placing or receiving telephone calls ubiquitously. The subscriber maintains a single telephone directory number and receives service no matter which IP network he is currently connected to. Under the present invention, subscribers can, for instance, move from a static network connection at work to a dial in network connection from home.
The present invention provides a method of managing call origination for subscribers on a packet data telephony network which includes a home location register. A subscriber registers a packet data communication (IP telephony) device with the home location register of the subscriber""s home packet data (IP) network, and uses the home location register to translate the subscriber""s packet data (IP) address into a E.164) telephone directory number.
The present invention also provides a method of managing call termination (i.e., call reception) for subscribers on a packet data telephony network which includes a home location register. The subscriber registers a packet data communication (IP telephony) device with the home location register of the subscriber""s home packet data (IP) network, and uses the home location register to translate the subscriber""s E.164) telephone directory number into a packet data (IP) address.
The present invention further provides a method of public switching telephone network based roaming call origination for IP telephony devices. The subscriber registers his IP telephony device on a remote IP network, and may originate calls from the IP telephony device on the remote network to a third party.
The present invention still further provides a method of public switching telephone network based roaming call termination (i.e., call reception) for IP telephony devices. An IP subscriber registers his IP telephony device on a remote IP network, and may receive calls on the IP telephony device on the remote network from a third party.
It is therefore an object of the invention to provide PSTN based network roaming for IP telephony devices.
It is a further object of the invention to provide SCP based management for IP telephony devices.
Some of the objects of the invention having been stated hereinabove, other objects will become evident as the description proceeds, when taken in connection with the accompanying drawings as best described hereinbelow.